Quantum Spin Hall Effect and Enhanced Magnetic Response by Spin-Orbit Coupling

TL;DR

This paper reveals a link between spin Hall conductivity and magnetic susceptibility in insulators, using it to predict bismuth as a quantum spin Hall material and proposing experimental tests.

Contribution

It introduces a theoretical relationship between spin Hall conductivity and magnetic susceptibility, guiding the prediction of quantum spin Hall effect in real materials like bismuth.

Findings

Bismuth is predicted to exhibit the quantum spin Hall effect.

The relationship between spin Hall conductivity and magnetic susceptibility is established.

Proposed experiments to verify the quantum spin Hall effect in bismuth.

Abstract

We show that the spin Hall conductivity in insulators is related with a magnetic susceptibility representing the strength of the spin-orbit coupling. We use this relationship as a guiding principle to search real materials showing quantum spin Hall effect. As a result, we theoretically predict that bismuth will show the quantum spin Hall effect, both by calculating the helical edge states, and by showing the non-triviality of the Z_2 topological number, and propose possible experiments.